Brush seals incorporate a large number of bristles (which comprise aligned wires or fibres) which are generally held at one end and free at the other. One known method of manufacture of such brush seals is to produce a tuft (or bundle) comprising a known number of bristles which are temporarily held together by some means. During subsequent manufacturing processes the individual tufts are placed between the front and back plates to form a brush seal. Once the brush seal has been assembled the temporary means of holding the tufts together is removed by an appropriate method to provide a uniform brush seal with a known number of bristles.